This was a result, he said, of a drop-off in the number of visits from desktop PCs to its products.

In addition, he said, the company wanted to avoid overloading its core Facebook and Instagram apps with paid-for content.

Introducing adverts to a product that had not featured them to date might therefore address investors’ concerns.

But one company-watcher said the move represented a “plan B”.

“When Facebook first spoke about trying to monetise Messenger, the whole idea was that it would be a big kind of customer service tool with people able to speak directly to brands to sort out problems,” said Sarah Vizard, content editor of Marketing Week.

“The pitch was that companies could save money by setting up AI [artificial intelligence] chatbots to do this.

“There are some brands that are using chatbots on Messenger, but it’s still seen as a bit of a gimmick.

“So, Facebook has been looking around for different ways to make money from Messenger and has obviously shifted its strategy a bit to think people will accept some ads within it.”-BBC